diff --git a/backends/cxxrtl/cxxrtl.cc b/backends/cxxrtl/cxxrtl.cc
index 237700b29..89e58622c 100644
--- a/backends/cxxrtl/cxxrtl.cc
+++ b/backends/cxxrtl/cxxrtl.cc
@@ -212,7 +212,7 @@ bool is_ff_cell(RTLIL::IdString type)
 
 bool is_internal_cell(RTLIL::IdString type)
 {
-	return type[0] == '$' && !type.begins_with("$paramod\\");
+	return type[0] == '$' && !type.begins_with("$paramod");
 }
 
 bool is_cxxrtl_blackbox_cell(const RTLIL::Cell *cell)